Now that Squeeze has been released, we (the pkg-xfce group) are
in the process of uploading 4.8 to Debian. And we are
uploading it to experimental for good reasons.

Not that 4.8 is broken, but the packages are, and we're
aware of it. Some packages are still in NEW, some are not uploaded
because of some licensing issues, some have not been uploaded
because we didn't yet have the time.

What does this mean for you? That you should *not* upgrade to
Xfce 4.8. Not all packages will be upgraded, and mixing
4.6 and 4.8 is a bad idea. We don't know yet what
will happen (and that's the whole point of uploading to
experimental), and it seems that there are issues indeed.

So unless you're willing to fix the problems, don't upgrade to
4.8. It's not complete and it *will* break your install. I
wouldn't recommend building and installing from our svn repository
(for the sames reasons) nor from another (since upgrade path won't
be guaranteed and we won't be able to fix them for you).

So please be patient, we will upload 4.8 to unstable at
one point, and there will still be polishing to be made if you want
to help.